1. Field of the Invention
The present invention relates to a substrate processing apparatus for developing a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display, a glass substrate for a photomask, a substrate for an optical disk or the like.
2. Description of the Background Art
A substrate developing apparatus is employed for developing a photosensitive film of photoresist or the like formed on a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display (LCD), a glass substrate for a photomask, a substrate for an optical disk or the like.
In relation to development of an exposed photosensitive film formed on the surface of a substrate in a semiconductor manufacturing process or an LCD manufacturing process, known is a developing apparatus discharging a developer from a spray discharge nozzle while horizontally holding the substrate and rotating the same about a vertical axis thereby uniformly and sufficiently supplying the developer to the overall surface of the rotated substrate for developing the photosensitive film or dropping a developer onto the substrate kept in a stationary state from a nozzle having a discharge width at least equivalent to the maximum width of the substrate while moving this nozzle in parallel with the surface of the substrate thereby heaping the developer on the overall surface of the substrate, for example.
The developing apparatus heaping the developer on the overall surface of the substrate for developing the photosensitive film of photoresist or the like generally rotates the substrate at a high speed after a lapse of a prescribed developing time from supply of the developer onto the surface of substrate for discharging a rinse such as pure water, for example, to the surface of the rotated substrate from a discharge nozzle while draining the developer off the substrate by centrifugal force and replacing the developer with the pure water on the overall surface of the substrate, in order to stop development of the photosensitive film with the developer. Thereafter the developing apparatus further continuously rotates the substrate for draining the rinse off the substrate and drying the substrate thereby ending the processing.
However, the conventional developing apparatus performs at least the processing of supplying the rinse while draining the developer for stopping development of the photosensitive film with the developer to the subsequent processing of draining the rinse and drying the substrate in the state rotating the substrate at a high speed, and hence the developer or the rinse drained off the substrate by centrifugal force is disadvantageously splashed back from the periphery to adhere the surface or the back surface of the substrate again and contaminate the substrate. Following further refinement of patterns, a fine pattern formed by the developer may collapse due to influence by the centrifugal force resulting from high-speed rotation of the substrate.
In the process of manufacturing a semiconductor device, for example, a slit scan development system is recently widely employed as one of methods of developing a photoresist film formed on the surface of a substrate such as a semiconductor wafer. This development system linearly horizontally moves a developer discharge nozzle having a slit discharge port substantially equivalent to or longer by about several mm than the diameter of a substrate from a first end to a second end of the substrate horizontally held in a stationary state by a substrate holding part while discharging a developer onto the substrate from the slit discharge port of the developer discharge nozzle for heaping the developer on the substrate. Thus, line width uniformity of a resist film pattern can be remarkably improved by heaping the developer while keeping the substrate stationary.
When the developer discharge nozzle moves at a speed of 50 mm/sec. in this slit scan development, for example, developing time difference of six seconds at the maximum results in a substrate of 300 mm in diameter. In a developing time of about 60 seconds applied to a conventional manufacturing process, development of photoresist substantially converges and hence the developing time difference resulting in the substrate surface does not appear as difference in work dimension exceeding allowance. In manufacturing of a recent semiconductor device, however, a hyperfine working technique is employed while allowance for work dimensions is strictly managed. Therefore, the difference in work dimension resulting from developing time difference, hardly regarded as problematic in general, recently comes into question as the case may be. When the developing time is reduced in order to improve the throughput, further, the difference in work dimension resulting from developing time difference disadvantageously gets remarkable.
Therefore, a scan rinse system of providing a rinse discharge nozzle supplying a rinse (pure water) onto a substrate for stopping development with a slit discharge port for heaping a developer through a developer discharge nozzle, thereafter holding a prescribed developing time and discharging the rinse onto the substrate from the slit discharge port of the rinse discharge nozzle while moving the rinse discharge nozzle at the same speed in the same direction as the developer discharge nozzle is proposed in order to eliminate the developing time difference in the substrate surface.
When a developer discharge nozzle (not shown) heaps a developer 301 on the overall upper surface of a substrate W horizontally held by a substrate holding part 310 and thereafter a rinse discharge nozzle 312 discharges a rinse 302 onto the substrate W from a slit discharge port thereof while horizontally moving from a first end to a second end of the substrate W as shown in FIG. 31A, however, the rinse 302 discharged from the rinse discharge nozzle 312 also flows frontward in the direction of movement of the rinse discharge nozzle 312, as shown in FIG. 31B. The rinse 302 flowing frontward from the rinse discharge nozzle 312 partially washes away the developer 301 located in front of the rinse discharge nozzle 312 from the substrate W. Therefore, it follows that development is stopped in front of the rinse discharge nozzle 312 before the rinse discharge nozzle 312 moves. Consequently, developing time difference in the surface of the substrate W cannot be efficiently eliminated and work dimension difference resulting from the developing time difference cannot be eliminated either.
FIGS. 48A to 48E are model diagrams showing exemplary developing steps through a developing apparatus capable of performing uniform development at a low cost.
As shown in FIG. 48A, a developer discharge nozzle 511 moves from a position on a side located outside a substrate 500 held in a stationary state by a substrate holding part 501 to a position on another side located outside the substrate 500 through the substrate 500 along with a rinse discharge nozzle 516. The developer discharge nozzle 511 is inclined in a direction opposite to a scanning direction A3 with respect to the substrate 500, in order to suppress flowage of a developer in the scanning direction A3 while inducing flowage of the developer in the direction opposite to the scanning direction A3 on the surface of the substrate 500 thereby improving uniformity of development and preventing development defects.
Then, the substrate 500 held by the substrate holding part 501 is rotated by 180xc2x0 as shown in FIG. 48B, and the developer discharge nozzle 511 moves along with the rinse discharge nozzle 516, which in turn supplies a rinse onto the substrate 500 thereby stopping development, as shown in FIG. 48C. A pure water discharge nozzle 512 cleans a resist film or the like provided on the substrate 500, as shown in FIG. 48D. Thereafter the substrate 500 is horizontally rotated about a vertical axis to be dried, as shown in FIG. 48E.
Thus, development can be stopped by supplying the rinse onto the substrate 500 from the rinse discharge nozzle 516 after supplying the developer onto the substrate 500 from the developer discharge nozzle 511, whereby a uniform developing time can be attained on the substrate 500. Further, the developer discharge nozzle 511 moves on the substrate 500 along with the rinse discharge nozzle 516, whereby the structures of moving elements are simplified and miniaturized for saving the space therefor. Consequently, uniform development can be performed at a low cost.
However, the aforementioned developing apparatus requires a motor (rotating/driving unit) for rotating the substrate 500 thereby drying the same, to hinder miniaturization of the developing apparatus or reduction of the space therefor. Further, a time of about 10 seconds is required for rotating the substrate 500 and drying the same, to result in reduction of the throughput of the development.
In the process of manufacturing a semiconductor device, for example, the slit scan development system is recently widely employed as one of methods of developing a photoresist film formed on the surface of a substrate such as a semiconductor wafer. This development system linearly horizontally moves a developer discharge nozzle having a slit discharge port on its lower end surface from a first end to a second end of a substrate horizontally held by a substrate holding part in a stationary state while discharging a developer onto the substrate from the slit discharge port of the developer discharge nozzle for heaping the developer on the substrate. Thus, line width uniformity of a resist film pattern can be remarkably improved by heaping the developer while keeping the substrate stationary. The scan rinse system supplying pure water (rinse) for stopping development after a lapse of a prescribed time from heaping of a developer while horizontally linearly moving a pure water discharge nozzle is also recently employed in order to further improve the line width uniformity of the pattern.
When selectively horizontally linearly moving the developer discharge nozzle and the pure water discharge nozzle respectively for discharging the developer and the pure water onto the substrate respectively, however, a driving system as well as control operations are complicated. Further, the developer discharge nozzle used in the slit scan development system and the pure water discharge nozzle used in the scan rinse system are manufactured with specific materials by specific working methods for attaining maximum process performance, leading to extremely high costs.
In addition, a driving system and a control system are disadvantageously complicated not only in the apparatus selectively moving the developer discharge nozzle and the pure water discharge nozzle respectively for discharging the developer and the pure water onto the substrate but also in an apparatus selectively moving a developer discharge nozzle and a pure water discharge nozzle to a central position of a substrate respectively for discharging a developer and pure water onto the substrate while rotating the substrate about a vertical axis.
A further conventional substrate processing apparatus moves a developer supply nozzle from a first end to a second end of a substrate for supplying a developer to the overall upper surface of the substrate and moves a rinse supply nozzle from the first end to the second end of the substrate at the same speed as that for moving the said developer supply nozzle after a lapse of a prescribed time for supplying a rinse to the overall upper surface of the substrate and stopping development on the surface of the substrate.
According to this substrate processing apparatus, the developing time can be rendered substantially identical on the overall upper surface of the substrate, whereby uneven development can be prevented while line width uniformity of a resist pattern after development can be improved.
However, the aforementioned substrate processing apparatus supplies the rinse at a feed rate for supplying the rinse to only a part of the substrate corresponding to a position of movement during movement of the rinse supply nozzle for attaining a substantially identical developing time on the overall upper surface of the substrate.
Therefore, a cleaning effect for the substrate is so insufficient that particles of dissolution products etc. resulting from development are retained on the substrate, leading to reduction of the product yield or the like.
The present invention is directed to a substrate processing apparatus supplying a developer to a substrate for developing the same and thereafter supplying a rinse for washing away the developer.
A substrate processing apparatus according to the present invention comprises a substrate holding element horizontally holding a substrate in a stationary state, a developer supplying moving element including a developer discharge port having a discharge width at least equivalent to the diameter of the substrate for moving from a developer supply start position on a first end of the substrate held by the substrate holding element to a developer supply end position on a second end and supplying a developer to the surface of the substrate, and a rinse supplying moving element including a rinse discharge port having a discharge width at least equivalent to the diameter of the substrate for moving from the developer supply start position to the developer supply end position after the developer supplying moving element supplies the developer to the overall surface of the substrate for supplying a rinse to the overall surface of the substrate from the rinse discharge port, while the rinse supplying moving element has a rinse suction port having a suction width at least equivalent to the diameter of the substrate at the back of the rinse discharge port in the direction of movement of the rinse supplying moving element so that the rinse supplying moving element moves from the developer supply start position to the developer supply end position after the developer supplying moving element supplies the developer to the overall surface of the substrate for supplying the rinse to the overall surface of the substrate from the rinse discharge port while recovering the supplied rinse from the rinse suction port.
The rinse can be recovered from the substrate while keeping the substrate in a stationary state.
Another substrate processing apparatus according to the present invention comprises a substrate holding element horizontally holding a substrate, a developer supply element having a slit developer discharge port for discharging a developer onto the substrate from the slit developer discharge port while relatively horizontally moving with respect to the substrate held by the substrate holding element and heaping the developer on the overall upper surface of the substrate, a rinse supply element having a slit rinse discharge port for discharging a rinse onto the substrate from the slit rinse discharge port while relatively moving in the same direction as the direction of relative movement of the developer supply element with respect to the substrate held by the substrate holding element for stopping development reaction with the developer, and an anti-flow element preventing the rinse discharged onto the substrate from the slit rinse discharge port of the rinse supply element from flowing frontward in the direction of the relative movement of the rinse supply element with respect to the substrate and preventing the developer on the substrate from being swept away frontward in the direction of the relative movement by the rinse.
The anti-flow element prevents the rinse discharged onto the substrate, whereby developing time difference can be eliminated on the surface of the substrate.
Still another substrate processing apparatus according to the present invention comprises a substrate holding element holding a substrate, a developer discharge nozzle discharging a developer, a processing solution discharge nozzle discharging a processing solution for stopping development, a gas injection nozzle injecting a gas for removing the developer and the processing solution from the substrate and drying the substrate, and a moving element moving the developer discharge nozzle, the processing solution discharge nozzle and the gas injection nozzle from a position on a first side located outside the substrate held by the substrate holding element in a stationary state to a position on a second side located outside the substrate through the substrate.
In this case, it is not necessary to rotate the substrate for drying the same, whereby no rotating/driving unit is required for rotating the substrate. Further, no time is required for a step of rotating the substrate, whereby the throughput of development is improved. Consequently, miniaturization, reduction of a space and improvement of production efficiency are enabled.
A further substrate processing apparatus according to the present invention comprises a substrate holding element horizontally holding a substrate, a solution discharge nozzle having a discharge port for discharging a developer onto the substrate from the discharge port, a developer supply source, and a developer supply pipe connecting the solution discharge nozzle and the developer supply source with each other in a channel manner, and the substrate processing apparatus further comprises a pure water supply source and a pure water supply pipe connected to the pure water supply source and communicatively connected to the solution discharge nozzle, for interposing a first on-off valve in the developer supply pipe while interposing a second on-off valve in the pure water supply pipe for selectively opening the first on-off valve and the second on-off valve.
The single solution discharge nozzle can discharge the developer and the pure water onto the substrate, whereby this substrate processing apparatus has a relatively simple driving system and relatively simple control operations, can be miniaturized, and can reduce the cost.
According to an aspect of the present invention, the substrate processing apparatus further comprises a developer recovery pipe communicatively connected to the solution discharge nozzle, a third on-off valve interposed in the developer recovery pipe, a recovery suction element sucking the contents of the solution discharge nozzle through the developer recovery pipe, and a recovery tank arranged between the solution discharge nozzle and the recovery suction element for recovering the developer sucked from the solution discharge nozzle.
Unused part of the developer remaining in the solution discharge nozzle can be recovered and reused after discharging the developer onto the substrate from the solution discharge nozzle, whereby consumption of the developer can be reduced.
According to another aspect of the present invention, the substrate processing apparatus further comprises a drain pipe communicatively connected to the solution discharge nozzle, a fourth on-off valve interposed in the drain pipe, and a drain suction element sucking the contents of the solution discharge nozzle through the drain pipe.
The pure water remaining in the solution discharge nozzle can be reliably discharged from the solution discharge nozzle after supplying the pure water onto the substrate.
A further substrate processing apparatus according to the present invention comprises a substrate holding element holding a substrate, a developer supply element supplying a developer from a first end to a second end of the main surface of the substrate held by the substrate holding element, a stop bath supply element supplying a stop bath from the first end to the second end of the main surface of the substrate after the developer is supplied to the main surface of the substrate, a detergent supply element supplying a detergent to the main surface of the substrate, and a control part causing the detergent to be supplied to the main surface of the substrate from the detergent supply element after the stop bath is supplied to the substrate. In the substrate processing apparatus, the detergent supply element includes: a detergent supply nozzle having a discharge port having a width substantially identical to or in excess of the diameter of the substrate, and a detergent supply nozzle moving element moving the detergent supply nozzle from a first end toward a second end of a position where the substrate holding element holds the substrate, and said control part causes said detergent to be supplied from the detergent supply nozzle while moving the detergent supply nozzle from the first end toward the second end of the position where the substrate is held or vice versa after the stop bath is supplied to the substrate.
The substrate supplied with the stop bath can be sufficiently cleaned.
Accordingly, an object of the present invention is to provide a substrate processing apparatus capable of preventing a substrate from contamination in the process of development.
Another object of the present invention is to provide a substrate developing apparatus capable of preventing pattern collapse with a developer in the process of development.
Still another object of the present invention is to provide processing equipment for a substrate capable of eliminating developing time difference in a substrate surface thereby eliminating work dimension difference resulting from the developing time difference when performing slit scan development/slit scan rinsing.
A further object of the present invention is to provide a developing apparatus enabling miniaturization, reduction of a space and improvement of production efficiency.
A further object of the present invention is to provide processing equipment for a substrate having a relatively simple driving system and relatively simple control operations and capable of reducing the cost.
A further object of the present invention is to provide a substrate processing apparatus capable of sufficiently cleaning a substrate supplied with a stop bath.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.